(Visual Basic 6.0) Extract PKCS7 from MIME and Decrypt

Extracts the base64-encoded PKCS7 body of a MIME message to a file, and then decrypts using Chilkat Crypt2.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

' This example assumes the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim mime As New ChilkatMime

Dim success As Long
success = mime.LoadMimeFile("c:/aaworkarea/EmailInBytes.txt")
If (success <> 1) Then
    Debug.Print mime.LastErrorText
    Exit Sub
End If

success = mime.SaveBody("c:/aaworkarea/smime.p7m")
If (success <> 1) Then
    Debug.Print mime.LastErrorText
    Exit Sub
End If

Dim crypt As New ChilkatCrypt2

success = crypt.AddPfxSourceFile("c:/aaworkarea/my.pfx","pfxPassword")
If (success = 0) Then
    Debug.Print crypt.LastErrorText
    Exit Sub
End If

' Indicate the public-key (PKCS7) encryption/decryption should be used:
crypt.CryptAlgorithm = "pki"

Dim inPath As String
inPath = "c:/aaworkarea/smime.p7m"
Dim outPath As String
outPath = "c:/aaworkarea/decrypted.dat"

success = crypt.CkDecryptFile(inPath,outPath)
If (success = 0) Then
    Debug.Print crypt.LastErrorText
    Exit Sub
End If

Debug.Print "Success."